import java.util.Random;
import java.util.Scanner;

public class test {
    public static void main(String[] args) {
        //Scanner scan = new Scanner(System.in);
        int count = 0;
        int mid = 0;
        for (int i = 0; i <= 100; i++) {
            mid = i;
            while(mid != 0){
                if(mid % 10 == 9){
                    count++;
                }
                mid /= 10;
            }
        }
        System.out.println("9的个数是："+count);
    }
}
